Downlink signal receiving method, terminal, and source base station

Abstract

This application provides a downlink signal receiving method, a terminal, and a source base station. The method includes: A terminal may receive downlink signals from a source base station and a target base station in a handover process. When receiving no downlink signal from the target base station, the terminal receives the downlink signal only from the source base station. In addition, after handover is completed, the terminal receives the downlink signal only from the target base station, so that the terminal can still receive the downlink signal from the source base station in the handover process. Therefore, downlink signal transmission interruption caused by the handover process may be reduced to 0 ms or nearly 0 ms. In other words, zero interruption or nearly zero interruption of data transmission may be implemented.

What is claimed is: 
     
         1 . A downlink signal receiving method, applied to a process in which a terminal is handed over from a source base station to a target base station, wherein the method comprises:
 receiving, by the terminal, a first message from the source base station, wherein the first message comprises a first indication, and the first indication is used to indicate the terminal to receive downlink signals on a same frequency; and   receiving, by the terminal, downlink signals from the source base station and the target base station based on the first indication.   
     
     
         2 . The method according to  claim 1 , wherein the receiving, by the terminal, downlink signals from the source base station and the target base station based on the first indication comprises:
 configuring, by the terminal, at least two processing resources based on the first indication, wherein one processing resource comprises a baseband resource and a fast fourier transformation (FFT), and the at least two processing resources correspond to a same carrier frequency;   receiving, by the terminal, the downlink signal from the source base station by using a first processing resource in the at least two processing resources; and   receiving, by the terminal, the downlink signal from the target base station by using a second processing resource in the at least two processing resources, wherein   the first processing resource is different from the second processing resource.   
     
     
         3 . The method according to  claim 2 , wherein if the terminal has a carrier aggregation capability, a bandwidth of a baseband resource comprised in the first processing resource is the same as a bandwidth of a baseband resource comprised in the second processing resource, and a size of an FFT corresponding to the first processing resource is the same as a size of an FFT corresponding to the second processing resource; or
 if the terminal does not have a carrier aggregation capability, a bandwidth of a baseband resource comprised in the second processing resource is less than or equal to a bandwidth of a baseband resource comprised in the first processing resource, and a size of an FFT corresponding to the second processing resource is less than or equal to a size of an FFT corresponding to the first processing resource, wherein the bandwidth of the baseband resource comprised in the second processing resource is less than or equal to a preset bandwidth threshold.   
     
     
         4 . The method according to  claim 1 , wherein the method further comprises:
 sending, by the terminal, a first capability indication to the source base station, wherein the first capability indication is used to indicate that the terminal has an intra-frequency receiving capability.   
     
     
         5 . The method according to  claim 1 , wherein the method further comprises:
 skipping adjusting, by the terminal, an automatic gain control (AGC) gain based on the first indication; or   skipping adjusting, by the terminal, an AGC gain based on a second indication, wherein the first message further comprises the second indication.   
     
     
         6 . The method according to  claim 5 , wherein the method further comprises:
 sending, by the terminal, a second capability indication to the source base station, wherein the second capability indication is used to indicate that the terminal has a capability of skipping adjusting the AGC gain.   
     
     
         7 . The method according to  claim 1 , wherein the method further comprises:
 setting, by the terminal, a fixed AGC gain based on a fading margin, wherein the first indication is further used to indicate the fading margin; or   setting, by the terminal, a fixed AGC gain based on a fading margin, wherein the first message further comprises a third indication, and the third indication is used to indicate the fading margin.   
     
     
         8 . A downlink signal receiving method, applied to a process in which a terminal is handed over from a source base station to a target base station, wherein the method comprises:
 generating, by the source base station, a first message, wherein the first message comprises a first indication, and the first indication is used to indicate the terminal to receive downlink signals on a same frequency; and   sending, by the source base station, the first message to the terminal.   
     
     
         9 . The method according to  claim 8 , wherein the method further comprises:
 receiving, by the source base station, a first capability indication from the terminal, wherein the first capability indication is used to indicate that the terminal has an intra-frequency receiving capability.   
     
     
         10 . The method according to  claim 8 , wherein the first indication is further used to indicate the terminal to skip adjusting an AGC gain; or
 the first message further comprises a second indication, wherein the second indication is used to indicate the terminal to skip adjusting an AGC gain.   
     
     
         11 . A terminal, used in a process in which the terminal is handed over from a source base station to a target base station, and comprising:
 a transceiver, configured to receive a first message from the source base station, wherein the first message comprises a first indication, and the first indication is used to indicate the terminal to receive downlink signals from the source base station and the target base station on a same carrier frequency; and   a processor, configured to receive the downlink signals from the source base station and the target base station based on the first indication through the transceiver.   
     
     
         12 . The terminal according to  claim 11 , wherein the processor is configured to configure at least two processing resources based on the first indication, wherein one processing resource comprises a baseband resource and a fast fourier transformation (FFT), and the at least two processing resources correspond to a same carrier frequency; and
 the transceiver is configured to: receive the downlink signal from the source base station by using a first processing resource in the at least two processing resources; and receive the downlink signal from the target base station by using a second processing resource in the at least two processing resources, wherein   the first processing resource is different from the second processing resource.   
     
     
         13 . The terminal according to  claim 12 , wherein if the terminal has a carrier aggregation capability, a bandwidth of a baseband resource comprised in the first processing resource is the same as a bandwidth of a baseband resource comprised in the second processing resource, and a size of an FFT corresponding to the first processing resource is the same as a size of an FFT corresponding to the second processing resource; or
 if the terminal does not have a carrier aggregation capability, a bandwidth of a baseband resource comprised in the second processing resource is less than or equal to a bandwidth of a baseband resource comprised in the first processing resource, and a size of an FFT corresponding to the second processing resource is less than or equal to a size of an FFT corresponding to the first processing resource, wherein the bandwidth of the baseband resource comprised in the second processing resource is less than or equal to a preset bandwidth threshold.   
     
     
         14 . The terminal according to  claim 11 , wherein the transceiver is further configured to send a first capability indication to the source base station, wherein the first capability indication is used to indicate that the terminal has an intra-frequency receiving capability. 
     
     
         15 . The terminal according to  claim 11 , wherein the processor is further configured to skip adjusting an automatic gain control (AGC) gain based on the first indication; or
 the first message further comprises a second indication, and the processor is further configured to skip adjusting an AGC gain based on the second indication.   
     
     
         16 . The terminal according to  claim 15 , wherein the transceiver is further configured to send a second capability indication to the source base station, wherein the second capability indication is used to indicate that the terminal has a capability of skipping adjusting the AGC gain. 
     
     
         17 . The terminal according to  claim 11 , wherein the first indication is further used to indicate a fading margin, and the processor is further configured to set a fixed AGC gain based on the fading margin; or
 the first message further comprises a third indication, the third indication is used to indicate a fading margin, and the processor is further configured to set a fixed AGC gain based on the fading margin.   
     
     
         18 . A source base station, used in a process in which a terminal is handed over from the source base station to a target base station, and comprising:
 a processor, configured to generate a first message, wherein the first message comprises a first indication, and the first indication is used to indicate the terminal to receive downlink signals from the source base station and the target base station on a same carrier frequency; and   a transceiver, configured to send the first message to the terminal.   
     
     
         19 . The source base station according to  claim 18 , wherein the transceiver is further configured to receive a first capability indication from the terminal, wherein the first capability indication is used to indicate that the terminal has an intra-frequency receiving capability. 
     
     
         20 . The source base station according to  claim 18 , wherein the first indication is further used to indicate the terminal to skip adjusting an AGC gain; or
 the first message further comprises a second indication, wherein the second indication is used to indicate the terminal to skip adjusting an AGC gain.